1. Field of the Invention
This invention relates generally to coating or plating a surface of an object with an electrolyte.
2. Description of Related Art
Coating or plating a surface of a substance with an electrolyte, or electroplating, has evolved. There are an ever-increasing number and widening types of applications of this branch of practical science and engineering. Some of the technological areas in which this is applied include macro-electronics, microelectronics, optics, optical-electronics, and sensors of most types. There are many other technological areas where electroplating is used.
Some industries use electroplating instead of other options. For example, the automobile industry uses chrome plating instead of evaporation, sputtering, chemical vapor deposition (CVD) and the like, to enhance the corrosion resistance of metal parts. Reasons for using electroplating include both economy and convenience.
By way of illustration it should be noted that that modern electroplating equips the practitioner with the ability to pre-design the properties of surfaces. In the case of electroforming this includes the properties of the whole part. Furthermore, the ability to deposit very thin multi-layers less than a millionth of a centimeter in thickness via electroplating is available.
Electroplating is often also called “electro-deposition,” and the two terms are used interchangeably. Electroplating occurs by electro-deposition, producing a coating, usually metallic, on a surface by the action of electric current. The deposition of a metallic coating onto the surface of an object is achieved by putting a negative charge on the object to be coated and immersing it into a solution, which contains a salt of the metal to be deposited.
In other words, the object to be plated functions as a cathode of an electrolytic cell. The metallic ions of the salt carry a positive charge and are thus attracted to the object. When they reach the surface of the negatively charged object that is to be electroplated, that object provides electrons to reduce the positively charged ions to metallic form.
In connection with electro-plating, many applications have a limited tolerance of the thickness of the plating formed by electroplating. Thus, it is desirable to control the thickness of the plating formed by electro-plating within a pre-determined tolerance.
The foregoing objects and advantages of the invention are illustrative of those that can be achieved by the various exemplary embodiments and are not intended to be exhaustive or limiting of the possible advantages which can be realized. Thus, these and other objects and advantages of the various exemplary embodiments will be apparent from the description herein or can be learned from practicing the various exemplary embodiments, both as embodied herein or as modified in view of any variation that may be apparent to those skilled in the art. Accordingly, the present invention resides in the novel methods, arrangements, combinations, and improvements herein shown and described in various exemplary embodiments.